Radio communication systems are used by many in modern society to communicate. Many varied communication services, both voice communication services and data communication services, are regularly effectuated by way of radio communication systems. And, as technological advancements permit, the types of communication services effectuable by way of radio communication systems shall likely increase.
Cellular communication systems are exemplary of radio communication systems that have high levels of usage. Cellular communication systems are typically constructed to provide wide-area coverage. And, their infrastructures have been installed over significant portions of the populated areas of the world. A user communicates by way of a radio communication system through use of a wireless device, a radio transceiver, sometimes referred to as a mobile station or user equipment (UE). Typically, access to a cellular communication system is provided pursuant to purchase of a subscription, either on a revolving, i.e., monthly basis, or on a pre-paid, time-usage basis. Cellular communication systems, operable pursuant to different operating standards, define radio air interfaces at different frequency bands, for instance, at the 800 MHz frequency band, at the 900 MHz frequency band, and at bands located between 1.7 GHz and 2.2 GHz.
Other types of radio communication systems are also widely used, for instance, Bluetooth (™)-based and IEEE 802.11b/g-based systems, implemented, e.g., as, WLAN (Wireless Local Area Network) systems, also provide for voice and data communications, generally over smaller coverage areas than their cellular counterparts. WLANs are regularly operated as private networks, providing users who have access to such networks the capability to communicate therethrough through the use of Bluetooth-capable or 802.11b/g-capable wireless devices. WLANs are sometimes configured to be connected to public networks, such as the Internet, and, in turn, to other communication networks, such as PSTNs (Public Switched Telephonic Networks) and PLMNs (Public Land Mobile Networks). Interworking entities also are sometimes provided to provide more-direct connection between the small-area networks and a PLMN. Various of the aforementioned systems are implemented at the 2.4 GHZ frequency band.
Radio communication systems are generally bandwidth-constrained. That is to say, bandwidth allocations for their operation are limited. And, such limited allocation of bandwidth, imposes limits upon the communication capacity of the communication system. Significant efforts have been made, and attention directed towards manners by which, to efficiently utilize the limited bandwidth allocated in bandwidth-constrained systems. Dual-polarization communication techniques are sometimes utilized. In a dual-polarization technique, data communicated at the same frequency is communicated in separate, polarized planes. Close to a doubling of the communication capacity is possible through the use of dual-polarization techniques. To transduce signal energy pursuant to a dual-polarization scheme, the wireless device is required to utilize a dual-polarized antenna, operable in the separate polarization planes. Use of dual-polarization techniques also are advantageous for the reason that the effects of multi-path transmission and other interference are generally reduced, thereby improving quality of signal transmission and reception.
A dual-polarized antenna is realizable, for instance, by feeding a square patch antenna at two orthogonal edges thereof by way of an edge feed or a probe feed. Generally, existing dual-polarized patch antennas are used in conjunction with two feeding-network circuits. Such existing antennas suffer from various limitations. For instance, separation distances between the feed connections are required to be great enough to prevent occurrence of coupling between the respective feeding lines. Excessive amounts of coupling results in high cross polarization levels.
As wireless devices are of increasingly small dimensions, packaged in housings of increasingly-smaller dimensions, problems associated with the cross-polarization levels are likely to become more significant. An improved, dual polarized antenna, constructed in a manner to reduce such deleterious problems is needed.
It is in light of this background information related to antennas for radio devices that the significant improvements of the present invention have evolved.